My brother, who lives at home, is abusive to my mum. I worry he’ll hit her. The Guardian.

I am the eldest of four children of a single mother. I have two sisters and a brother, who is the second child. He is now 40, but does not have a career, friends or money. He still lives at home with our mother and does not contribute to bills.

Our mother worked hard for us and we never went without. There were money problems, but the rest of us were resilient enough to deal with them. We three girls have careers, partners and children and have been living independently for years.

My brother, however, plays the victim card. For example, he blames my mum for pushing him into the wrong degree – not true. He has done odd jobs over the years. He worked in one place for a long time but refused to go for higher-paying management positions. He feels he is too intelligent for such roles.

This has gone on for the past 20 years. He is perpetually angry, abusive and belligerent with us. When he is around non-family members, he is charming but with us he is rude and aggressive. He shouts at and abuses my mum, and my biggest fear is that he will hit her one day.

As a family we have offered to pay for counselling (he refused), we have given him money and bought him things. But he doesn’t appreciate it. He seems to think he has suffered some kind of injustice in life. He doesn’t take any responsibility for his life and even now will say that his predicament is everyone else’s fault. He refers to things that happened 20 years ago, and makes things up from the past to justify his victim status. He will say that we ruined his life and it’s because he did what we “wanted”.

He has been given opportunities to live away from home, but refuses. He lives with my mum while resenting and blaming her.

I have told my mum to kick him out, but she is reluctant. I don’t know how to make her be stronger. He acts like a baby, so she treats him like one. She was not this soft on the rest of us, especially me. I no longer speak to my brother.

I have said my mum should say that he should have therapy or move out. If he ends up on the streets, so be it. We have tried for years. I am sick of it. My mum is in her 70s. She no longer has the strength for the arguments.

I wasn’t sure how seriously worried you were about your mother being hit, as it wasn’t the focus of your much longer letter. If your mother is ever in danger she must dial 999 – assault is a criminal offence. I have also put a link at the bottom of the column, which you may find useful regarding the other aspects of abuse you mention.

I wonder if, growing up, you had to adopt a mothering role with your brother? You seem to have more of a parental relationship with him, rather than a sibling one. How do your sisters feel? Where is/was your dad? When did he leave the picture and why? Sometimes it’s what you can’t see, what isn’t mentioned, that is incredibly relevant.

I contacted psychotherapist Leila Bargawi (childpsychotherapy.org.uk), who notes that you seem quite “critical that he wasn’t more resilient”. There does seem to be a lot of disdain for him – the only boy. Bargawi also wonders if there was a narrative in your family about the men being losers. Maybe they were, but if it were presented as a gender, rather than person-specific thing (men are hopeless; women are resourceful and resilient), that may have had a big impact on all of you, but especially on your brother growing up without, it seems, a positive male role model.

Bargawi also wonders if somewhere along the line, unconsciously, your mother and brother were company for one another and if in some way “your brother has actually protected you all. He was the one who stayed at home while you were all able to go and do your own thing.” Maybe your brother felt overly responsible towards your mother, hence him saying that he did what you all wanted him to. Maybe this responsibility has now turned to resentment.

There is something “quite adolescent in your brother’s behaviour”, notes Bargawi, who says, “his emotional development may not have gone to plan”. And we both wondered if, in some way – subconsciously – your mother was getting something out of him being at home (and vice versa, despite his anger). This will seem incredible, but nowhere in your letter did I get a sense of how your mother felt about all this – only about how you feel. Your mother, by your own admission, is reluctant to chuck him out.

What can you do? Well, you cannot make your mum chuck him out, any more than one of your children in the future could make you throw out one of their siblings. Bargawi suggests that perhaps you can “find it in you to be supportive. Maybe remember a time in childhood when you got on. If he is always going on about his childhood, maybe there is something about that time that he needs to unpack.”

I think you need to ask yourself some questions: “Why am I so angry with my brother? What do I want to achieve and is it achievable, and what would happen if I did nothing?”